Rod guide and centralizer

ABSTRACT

A POLYURETHANE ROD GUIDE AND CENTRALIZER FOR USE ON SUCKER RODS EXTENDING LONGITUDINALLY THROUGH PRODUCTION TUBING SUCH AS US USED IN PUMPING FLUIDS TO THE SURFACE IN OIL WELLS WHEREIN THE ROD GUIDE AND CENTRALIZER SURROUND THE ROD TO POSITION IT GENERALLY AXIALLY OF THE TUBING TO PREVENT ENGAGEMENT OF THE ROD WITH THE TUBING WHEN SUCH RODS ARE RECIPROCATED THEREIN FOR ACTUATING AS WELL PUMP CONNECTED TO THE SUCKER RODS.

Feb. 2, 1971 N. MORRIS ROD GUIDE AND CENTRALIZER Filed bee. 18. 1.968

M0 f7 J INVENTOR 71 f 0 6 A -iQKQxAQAAQ 7 i: Ii ...i| lllllll 0 4 a aATTORNEYS United States Patent Oifice 3,560,060 Patented Feb. 2, 19713,560,060 ROD GUIDE AND CENTRALIZER Nate Morris, 10234 Metronome,Houston, Tex. 77042 Filed Dec. 18, 1968, Ser. No. 784,667 Int. Cl. E21b17/10; F16c N26 US. Cl. 308-4 1 Claim ABSTRACT OF THE DISCLOSURE Apolyurethane rod guide and centralizer for use on sucker rods extendinglongitudinally through production tubing such as is used in pumpingfluids to the surface in oil wells wherein the rod guide and centralizersurround the rod to position it generally axially of the tubing toprevent engagement of the rods with the tubing when such rods arereciprocated therein for actuating as well pump connected to the suckerrods.

BACKGROUND OF THE INVENTION (1) Field of the invention The presentinvention pertains to a polyurethane sucker rod guide and centralizerfor use in production tubing and particularly plastic-lined tubing topermit low friction engagement between the sucker rod guides and thetubing at those points along the string of sucker rods Where engagementbetween such rods and tubing occur to provide a minimum of wear anddamage to the plastic coated inner surface of the tubing.

(2) Description of the prior art In mechanical oil well pumpingapparatus, lengths of solid rods, known as sucker rods, are coupledtogether so as to extend down into a string of production tubing forconnecting mechanical pumping equipment at the surface to a well pumpdisposed in the well. As the sucker rod string is reciprocated in thetubing to actuate the pump for pumping well fluids upwardly through theproduction tubing to the surface, such string of sucker rods normallyengages the inner surface of the tubing at various spaced pointsbecause, more often than not, the string of tubing and the well bore arecrooked rather than straight. The engagement by the reciprocating suckerrods with the inner surface of the tubing at various points causes wearon the rods and the tubing when the rods are reciprocated therein.Various rod guides have been suggested to position the sucker rod stringso as to minimize engagement between the sucker rods and the tubing;however, the rod guides frequently cause wear and are particularlytroublesome when employed in a tubing string that is internally coatedor lined with a plastic film which is provided to inhibit corrosion ofthe tubing.

SUMMARY The present invention pertains :to a polyurethane rod guide andcentralizer which is secured to a sucker rod and which comprises alongitudinally extending cylindrical body having annular surfaces at itsopposite ends tapered inwardly toward the rod on which a rod guide iscarried and which includes a plurality of circumferentially spacedlongitudinally extending flutes or channels which are proyided in theouter surface of the cylindrical body and tralizer which reduces rod,coupling and tubing wear in sucker rod pumped wells and facilitates theuse of internally coated tubing having a plastic lining in such wells.

Another object of the present invention is to provide a new and improvedsucker rod guide and centralizer wherein the guide comprises alongitudinally extending polyurethane body having an outer cylindricalsurface and having annular surfaces at its opposite ends taperedinwardly toward the longitudinal axis of such cylindrical body. Aplurality of circumferentially spaced longitudinally extending fiutes orchannels are disposed at an angle to the longitudinal axis of the suckerrod guide or body and extefid longitudinally of the body from one of theannular tapered end surfaces to the other to provide relatively sharpedges for cutting or scrapping paraffin off of the inner -surface of theproduction tubing when such rod guides engage or rub against suchtubing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. Us a longitudinal view partly insection and partly in elevation showing the sucker rod guide andcentralizer of the present invention positioned on a sucker rod disposedin a plastic-lined joint of tubing;

FIG. 2 is a sectional view taken on line 2-2 of FIG. 1 showing -detailsof construction of the sucker rod guide and centralizer apparatus of thepresent invention; and

FIG. 3 is a sectional view taken on line 3--3 of FIG. 1 showingadditional details of construction of the sucker rod guide apparatus ofthe present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Briefly, as shown in FIG. 1 ofthe drawings, the sucker rod guide and centralizer apparatus of thepresent invention is designated generally G and is shown mounted on asolid sucker rod 4 that extends generally axially of the length oftubing 6 which, as shown, is internally coated or linedlwith a plasticfilm 7. The sucker rod guide G is formed of polyurethane and comprises agenerally cylindrical body 11 having annular tapered end portions 12 and13 which are inclined inwardly toward the longitudinal axis of suchcylindrical body. Laterally extending surfaces 19 and 20 which aretransverse of the longitudinal axis of the body 11 are provided adjacenteach end of the tapered surfaces 12 and 13. The body 11 is splitlongitudinally at 21 to enable the body to be installed on the rod 4 byspreading the split portion and inserting the rod 4 laterally into thecentral longitudinally extending opening or passage at 23 which extendsaxially through the body 11. An epoxy resin 20' or other suitablebonding agent is employed to glue or bond the facing edges of the splitportion 21 together and for also securing the body 11 to the rod 4.

circumferentially spaced flutes or channels 24 are provided on theexterior of the body 11 and extend longitudinally thereof to facilitatethe flow of well fluids around the guide G through the tubing 6. Asshown, such flutes or channels 24 extend from one tapered end portion 12to the tapered end portion 13 at the opposite end of the body 11.

The flutes or channels 24 are preferably formed with a bottom surface 26and with side surfaces 27 and 28 being disposed at substantially rightangles to such surface 26.

It will be noted that the flutes 24 are disposed at an angle to thelongitudinal axis of the body 11 so that the edges 29, formed at eachend of the channels where the sides 27 and 28 intersect the tapered ends12 and 13, present a sharp cutting edge which tends to cut or scrape anyparafiin off of the inner surface of the tubing 6 when the guide body 11bumps or rubs against such tubing.

In using the polyurethane sucker rod guide and centralizer of thepresent invention, it will be appreciated that the body 11 may beatfixed to the sucker rod 6 or to the sucker rod box couplings at theends of the rods (not shown) at desired intervals either by molding thebody 11 onto the rod 6 or by securing the body 11 thereon with asuitable bonding agent such as epoxy resin. With the bodies 11 thuspositioned on the sucker rod at longitudinally spaced intervals, thesucker rod string may be reciprocated in the tubing 6 with a minimum ofrubbing or abrasion between the inner surface of the tubing 6 and therod string 4. Also, it will be appreciated that the polyurethane suckerrod guides G are chemically resistant to Well fluids and gasesencountred in oil and gas wells as Well as to chemicals normally used intreating oil wells and that such polyurethane guide G does not produce aparaffin build up as parafiin does not readily adhere well to suchpolyurethane guides.

The foregoing disclosure and description of the invention areillustrative and explanatory thereof, and various changes in the size,shape, and materials as well as in the details of the illustratedconstruction may be made within the scope of the appended claim Withoutdeparting from the spirit of the invention.

What is claimed is:

1. A sucker rod guide and rod centralizer for use in plastic coatedtubing comprising:

(a) a body having a cylindrical outer surface extending longitudinallythereof;

(b) an annular end surface at each end of such cylindrical outer surfacetapered inwardly toward the longitudinal axis of such cylindrical body;

(0) a plurality of circumferentially spaced longitudinally extendingflutes formed in said body, said flutes being disposed at an angle tothe longitudinal axis of said body and communicating the tapered annularend surfaces at the opposite ends of said body;

(d) said flutes including a flat bottom surface and a pair ofcircumferentially spaced side surfaces disposed at substantially rightangles to said bottom surface and intersecting the outer cylindricalsurface of said body;

(e) said body being split longitudinally along the bottom surface of oneof said flutes; and

(f) a suitable bonding agent bonding the faces of the split together andsecuring the body on the rod.

References Cited UNITED STATES PATENTS 2,690,934 10/1954 Holcombe 30843,049,382 8/1962 Ell 3084 3,360,846 l/l968 Schellstede et al. 166241X3,414,337 12/1968 Sable 308-4 MANUEL A. ANTONAKAS, Primary Examiner US.Cl. X.R.

